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Parallel computation of regional CORS network corrections based on ionospheric-free PPP / Linyang Li in GPS solutions, vol 23 n° 3 (July 2019)
[article]
Titre : Parallel computation of regional CORS network corrections based on ionospheric-free PPP Type de document : Article/Communication Auteurs : Linyang Li, Auteur ; Zhiping Lu, Auteur ; Zhengsheng Chen, Auteur ; et al., Auteur Année de publication : 2019 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes de référence et réseaux
[Termes IGN] Continuously Operating Reference Station network
[Termes IGN] correction troposphérique
[Termes IGN] fractional cycle bias
[Termes IGN] Global Navigation Satellite System
[Termes IGN] positionnement cinématique en temps réel
[Termes IGN] positionnement ponctuel précis
[Termes IGN] retard troposphérique zénithal
[Termes IGN] station de référenceRésumé : (auteur) Global navigation satellite system real-time processing requires low latency, high timeliness, and high computational efficiency. A typical application is providing corrections using data from a regional Continuously Operating Reference Station (CORS) network. Usually the wide-lane and narrow-lane fractional cycle biases (FCBs) are determined at the server and broadcast to users to fix undifferenced ambiguity. Also, a tropospheric model is established at the server and broadcast to users to obtain accurate and reliable a priori zenith total delays for precise point positioning (PPP) using the ionospheric-free (IF) observation combination. Currently, serial methods are typically applied, i.e., all reference stations are involved in estimating the wide-lane and narrow-lane FCBs and establishing a regional tropospheric delay model. To improve the efficiency and shorten the latency, we develop a parallel computation method for regional CORS network corrections based on IF PPP by adopting a multicore parallel computing technology task parallel library, wherein parallel computations involving the FCBs, tropospheric delays, and tropospheric model are successively performed based on data parallelism, in which the same operation is performed concurrently on elements in an array, and task parallelism, which refers to one or more independent tasks running concurrently. Data covering four seasons from the Hong Kong and southwestern America CORS networks are utilized in the experiment. The single differenced FCBs between satellites are determined within each full pass, and a tropospheric model with an internal accuracy better than 1.4 cm and an external accuracy better than 1.6 cm is derived at the server. With the parallel implementation, the speedup ratios of FCB estimation and tropospheric modeling are 1.79, 3.15, 5.59, and 9.69 times higher for dual-core, quad-core, octa-core, and hexadeca-core platforms, respectively, than for a single-core platform. Numéro de notice : A2019-196 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s10291-019-0864-9 Date de publication en ligne : 13/05/2019 En ligne : https://doi.org/10.1007/s10291-019-0864-9 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=92650
in GPS solutions > vol 23 n° 3 (July 2019)[article]Processing of GNSS constellations and ground station networks using the raw observation approach / Sebastian Strasser in Journal of geodesy, vol 93 n°7 (July 2019)
[article]
Titre : Processing of GNSS constellations and ground station networks using the raw observation approach Type de document : Article/Communication Auteurs : Sebastian Strasser, Auteur ; Torsten Mayer-Gürr, Auteur ; Norbert Zehentner, Auteur Année de publication : 2019 Article en page(s) : pp 1045 - 1057 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] analyse diachronique
[Termes IGN] antenne GNSS
[Termes IGN] constellation GNSS
[Termes IGN] données GPS
[Termes IGN] erreur systématique
[Termes IGN] étalonnage d'instrument
[Termes IGN] Global Orbitography Navigation Satellite System
[Termes IGN] horloge du satellite
[Termes IGN] orbitographie
[Termes IGN] position
[Termes IGN] repère de référence
[Termes IGN] retard ionosphèrique
[Termes IGN] station GNSS
[Termes IGN] station GPSRésumé : (auteur) This article describes the raw observation approach as implemented at Graz University of Technology to determine GNSS products like satellite orbits, clocks, and station positions. To assess the performance of the approach, 15 years (2003–2017) of observations from a network of 245 globally distributed IGS stations to the GPS constellation were processed on a daily basis using the IGS14 reference frame and antenna calibrations. The resulting products are evaluated against those determined by IGS analysis centers. Orbit fit quality relative to the IGS combination is comparable to the best-fitting solutions used for evaluation. Starting from early 2017, when the IGS switched to IGS14, the determined orbits fit better to the IGS combination than any other considered solution. Midnight discontinuities show good internal orbit consistency and no noticeable satellite block-dependency. Satellite clocks are comparable to the considered IGS analysis center solutions. Station positions differ from the IGS combination on a similar level to the solutions they were evaluated against. The temporal repeatability of station positions is slightly better than that of the IGS combination. The quality of resulting GNSS products confirms that the raw observation approach is well suited for the task of determining satellite orbits, clocks, and station positions. It provides an alternative to well-established approaches used by IGS analysis centers and simplifies the introduction of additional observables from new and modernized GNSS. Numéro de notice : A2019-358 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-018-1223-2 Date de publication en ligne : 13/12/2018 En ligne : https://doi.org/10.1007/s00190-018-1223-2 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=93426
in Journal of geodesy > vol 93 n°7 (July 2019) . - pp 1045 - 1057[article]Spatial information recovery in the desert using LMS-based geodetic network adjustment / Eva Stopková in Survey review, vol 51 n° 367 (July 2019)
[article]
Titre : Spatial information recovery in the desert using LMS-based geodetic network adjustment Type de document : Article/Communication Auteurs : Eva Stopková, Auteur Année de publication : 2019 Article en page(s) : pp 334 - 344 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Topographie
[Termes IGN] compensation de coordonnées
[Termes IGN] compensation par moindres carrés
[Termes IGN] désert
[Termes IGN] Egypte
[Termes IGN] fouille archéologique
[Termes IGN] réseau géodésique local
[Termes IGN] réseau géodésique spécifique
[Termes IGN] site archéologiqueRésumé : (Auteur) This paper describes the local coordinate system recovery at the archaeological site Tell el-Retaba (Egypt), without any GNSS technology or the positioning in an official reference frame available. Completely destroyed control points were restored using geodetic network adjustment based on terrestrial observations and multi-epoch solution of the Least Mean Square models, and transformed into the original local coordinate system using identical points located on ancient mud-brick structures in former trenches. However, current and past measurements of excavated objects fit almost perfectly. Statistical and empirical tests indicate that the outliers correspond with measurements in harsh desert conditions. Numéro de notice : A2019-362 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/00396265.2018.1459360 Date de publication en ligne : 23/04/2018 En ligne : https://doi.org/10.1080/00396265.2018.1459360 Format de la ressource électronique : URL Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=93439
in Survey review > vol 51 n° 367 (July 2019) . - pp 334 - 344[article]Du NRTK vers le PPP-RTK, un exemple avec TERIA / Paul Chambon in XYZ, n° 159 (juin 2019)
[article]
Titre : Du NRTK vers le PPP-RTK, un exemple avec TERIA Type de document : Article/Communication Auteurs : Paul Chambon, Auteur Année de publication : 2019 Article en page(s) : pp 44 - 49 Note générale : Bibliographie Langues : Français (fre) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] mesurage de pseudo-distance
[Termes IGN] positionnement cinématique en temps réel
[Termes IGN] positionnement ponctuel précis
[Termes IGN] précision centimétrique
[Termes IGN] TeriaRésumé : (auteur) TERIA is a NRTK service which enables the achievement of centimeter accuracy within a few seconds. The first limitation which is reported by the user at our assistance is that to have access to the service the customers need an Internet connection. Indeed the NTRIP protocol is based on http and need a TCP/IP connection to enable to connect to our server to receive the corrections. To be able to counter this limitation we have to work to change the format of the corrections. In NRTK our server needs the position of the rover to send the right corrections. Another approach consists to use PPP, which can be broadcasted but such services need 20 to 30 minutes to reach centimeter accuracy. So we work to combine PPP and NRTK to enable to have the NRTK performance with the advantage of PPP. For that we developped PPP-RTK corrections, which is PPP augmented with ionosphere and troposphere model. So we were able to broadcast all data to correct GNSS pseudo range in an area. Another limitation was that the rover is not able to use PPP-RTK corrections as it’s not standardize. So we decided to counter also this limitation using a Library which can be installed in the rover and convert the PPP-RTK corrections in NRTK type VRS corrections which is fully standard in RTCM3.So our approach allowed us to broadcast corrections to enable GNSS rover to achieve centimeter accuracy in less than one minute. So we started a service transmitting such corrections through a geostationary satellite to cover area that are not covered by internet terrestrial networks (GSM, Wi-Fi ...). Also PPP-RTK has a lot of advantages to compared to NRTK and will certainly become a standard in the future, but as every new development it needs time for the industrial companies to agree on a standard. Numéro de notice : A2019-290 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=93157
in XYZ > n° 159 (juin 2019) . - pp 44 - 49[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 112-2019021 RAB Revue Centre de documentation En réserve L003 Disponible Reliability analysis for non-distorting connection of engineering survey networks / Witold Proszynski in Survey review, vol 51 n° 366 (May 2019)
[article]
Titre : Reliability analysis for non-distorting connection of engineering survey networks Type de document : Article/Communication Auteurs : Witold Proszynski, Auteur ; Slawomir Łapiński, Auteur Année de publication : 2019 Article en page(s) : pp 219 - 224 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Navigation et positionnement
[Termes IGN] compensation de coordonnées
[Termes IGN] fiabilité des données
[Termes IGN] génie civil
[Termes IGN] réseau géodésique spécifique
[Termes IGN] transformation de HelmertRésumé : (Auteur) A non-distorting network connection is a complex procedure consisting of a local network adjustment and a subsequent Helmert transformation into the connection points without changing the scale, i.e. isometry transformation. Since a joint adjustment model proposed for this connection in the earlier publication did not turn out sufficient to create a detailed reliability description for the whole procedure, reference had to be made to the original two-step approach. The reliability measures for a joint model and for each of the above mentioned procedural steps of the connection are being analysed. It is shown that the reliability description as based on indices obtained from the joint model should be supplemented with the indices from the two-step model. A specific property of the connection concerning mutual controllability of coordinates of the connection points is formulated on the basis of the Helmert transformation. The theory is illustrated on some numerical examples. Numéro de notice : A2019-193 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/00396265.2018.1425605 Date de publication en ligne : 24/01/2018 En ligne : https://doi.org/10.1080/00396265.2018.1425605 Format de la ressource électronique : URL Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=92639
in Survey review > vol 51 n° 366 (May 2019) . - pp 219 - 224[article]De la carte de Cassini à la géoplateforme de l’État / Daniel Bursaux in Responsabilité et environnement, n° 94 (Avril 2019)PermalinkConstellations, réseaux permanents, PPP : état des lieux / Laurent Morel in Géomètre, n° 2168 (avril 2019)PermalinkA new relationship between the quality criteria for geodetic networks / Ivandro Klein in Journal of geodesy, vol 93 n° 4 (April 2019)PermalinkLe réseau GPS permanent (RGP) de l'IGN / Sébastien Saur in Géomètre, n° 2168 (avril 2019)PermalinkLes services Teria / Paul Chambon in Géomètre, n° 2168 (avril 2019)PermalinkTeria : la géolocalisation de haute précision / Paul Chambon in Géomètre, n° 2168 (avril 2019)PermalinkDévelopper l’Afrique, grâce au recensement des stations GNSS permanentes / Derrick Koome in XYZ, n° 158 (mars 2019)PermalinkLe nivellement de Saint-Germain-en-Laye / Alain Coulomb in XYZ, n° 158 (mars 2019)PermalinkUtilisation d’infrastructures géodésiques mondiales pour la réalisation nationale / Raphaël Legouge in XYZ, n° 158 (mars 2019)PermalinkCombined orbits and clocks from IGS second reprocessing / Jake Griffiths in Journal of geodesy, vol 93 n° 2 (February 2019)Permalink